GB2147197A - Suction devices - Google Patents

Abstract

A suction/blow device is generally indicated at 10 and comprises a body 11, compressed air inlet 16 and outlet 21, a valve 12 and a control element 13 which is axially turnable at right angles in the body 11.The body 11 defines a suction nozzle 14 which opens into a chamber 15 and the body 11 and control element 13 together define a restricted passage 19 and a suction passage 20. By suitable adjustment of the control element 13 the compressed air can be made either to blow through the nozzle 14 or to create a suction at the nozzle. A bleed hole 23 is provided. <IMAGE>

Description

SPECIFICATION Suction Devices This invention relates to suction devices and in particular, but not exclusively, to such devices when incorporated in a blow gun.

Almost all machining operations, whether it be a dentist drilling or a piece of metal being cut on a lathe, result in swarf which becomes scattered over the machine area and must be cleared away. The common solution is to provide the operator with compressed air or blow guns which enable the swarf to be blown off the machine or out of the tooled part on to the surrounding floor. However, this can be extremely dangerous as fine slivers of metal fly up into the air and can become lodged in people's eyes.

The disposal of other types of waste is often problematic. For example, with the normal design of suction pump very great care has to be taken if the device is to be used with sharp waste or dirty waste such as sump oil.

It is an object of this invention to provide a device which improves the removal or disposal of certain waste material.

From one aspect the invention consists in a suction device having a suction opening and a compressed fluid path comprising an inlet, a restricted passage, a suction passage and an outlet, the suction passage communicating with the suction opening and the outlet and the restricted passage debouching into the suction passage intermediate the opening and the outlet, so that fluid flowing from the restricted passage is directed towards the outlet to create a depression in the suction passage to provide suction at the opening.

In a preferred embodiment a restricted passage surrounds the suction passage and its outlet is directed at a angle to the axis of the suction passage. The device is dimensioned such that material drawn in through the opening by the depression is delivered to the compressed fluid stream and from there passes through the outlet to the waste reservoir. The outlet and the reservoir may be connected by a porous pipe for retaining material sucked up by the device but which allows the escape of fluid. The device may also include a valve for controlling the flow of fluid in the fluid path.

The device may further comprise selection means for substantially closing-off the suction passage from the outlet to create a jet of compressed fluid through the opening and in this construction the device is both a suction device and a "blow-gun".

Preferably the device includes a body and the selection means comprises a control element rotatably mounted in the body, the control element defining the downstream end of the suction passage whereby rotation of the control element with respect to the body connects and disconnects the suction passage and the outlet. The restricted passage may be defined by the body and the control element and the control element may be shaped such that rotation of it does not affect the restricted passage.

A bleed passage for connecting the suction passage to the outlet when the selection means is in its closed-off position may be provided.

From another aspect the invention consists in a blow gun having a nozzle and a compressed fluid path for supplying compressed fluid to the nozzle and means for communicating the fluid path to atmosphere whenever the nozzle becomes obstructed.

The invention also consists in a tool having a suction mode and a blow mode and having no moving operational parts.

The invention further includes an attachment device comprising a suction device as defined above and further comprising a sucker or the like surrounding the suction opening. The attachment device may be mounted on a lifting arm orthe like to provide a lifting device.

Although the invention has been defined above it will be appreciated that it is not limited to these definitions and includes any inventive combination of the features listed above or the features of the device described below. Further, the main object of the invention has been stated, but it is to be understood that the invention may include devices which do not fulfill that object.

The invention may be performed in various ways and a specific embodiment, with modifications, will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a sectional view of a gun in its vacuum mode; Figure 2 is an end view of the gun of the Figure 1; Figure 3 is a corresponding sectional view of Figure 1 but showing the gun in its blow mode; and Figure 4 is an end view of the gun shown in Figure 3.

A suction/blow device is generally indicated at 10 in thefigures and comprises a gun shaped body 11, a valve 12 and a control element 13 which is rotatably mounted in the body 11. The body 11 defines a suction opening or nozzle 14 which opens into a chamber 15 for receiving the control element 13.

The body 11 and control element 13 together define a compressed air path 16 which comprises an air inlet 17, a control valve 12, a restricted passage 19, a suction passage 20 and an outlet 21. The restricted passage 19 is formed by an annular cut-out on the outer surface of the generally cylindrical control element 13 and debouches into the section passage 20 by means of a rearwardly facing inclined annular outlet 22.

The control element is further formed with a bleed passage 23 which extends at right angles to the downstream end of the suction passage 20. The control element is sealed with the body by means of O-rings 24 and is held in the body by a screwthreaded retaining device 25. A handle 26, formed integrally with the control element 13 projects through the retaining device 25 to enable rotation of the control element.

In Figure 1 the device is shown in its suction mode and operates in the following manner. When the knob 27 of the control valve 18 is depressed compressed airflows from a source (not shown) up through the air inlet 17 into the restricted passage 19. As the pressure of the air is maintained substantially constant the air speed in the passage is very considerably increased with the result that the passage of the fast moving air into the broad suction passage 20 creates a depression within the suction passage 20 and hence a suction at the opening 14.

Thus the operator can suck up swarf or the like by passing the suction opening 14 over the surface to be cleaned and depressing the valve knob 27. Swarf drawn into the opening by the depression in the suction passage 20 gets caught in the fluid stream and passes rapidly out of the outlet 21.

Dependent on the type of waste being collected the outlet 21 can be connected to a variety of reservoirs which will filter the waste from the air-stream. Indeed the connection between the outlet 21 and the reservoir (not shown) may itself be porous to enhance the filtering effect.

If it is desired to blow the waste material away, in the traditional manner, then the control element 13 is rotated, by means of its handle 26, through 90 so that it is in the position shown in Figures 3 and 4. In this position the suction passage 20 is substantially closed off from the outlet 21 with the result that the air strikes the closed end of the suction passage and rebounds out through the opening 14. The suction passage 20 is still connected to the outlet 21 by means of the bleed passage 23 so that in the event of the opening 14 becoming blocked the air will pass out through the outlet. This makes the device much safer in its blow mode because it means that if the jet comes into contact with the person's hands or other part of his body the pressure of the jet drops rapidly.

It will be seen that there are no moving operational parts in the device; the only elements which move are the control element and the valve knob. This means that the device can readily handle either sharp or dirty waste because there are no expensive items such as motors or pumps which can become damaged.

The opening or nozzle 14 may be internally or externally threaded to receive either jet defining devices or suction tools. For example, if it is desired to clean out a machine bore or a sump tank a flexible tube can be connected to the opening 14 with the result that the suction can be located at points far out of the operators reach.

In addition the device can be turned into a handling or lifting device by attaching a sucker-cup to surround the opening. This would be particularly useful for lifting sheet metal on to a machine for machining and can form a lifting device for a robot arm. If the device is to be operated automatically then the valve 18 can be dispensed with and the device merely controlled by pulsed compressed air.

Although the device has been mainly described in connection with machine tools it can be used in any operation where a cheap suction device or a suction! blow device is required. The device could also be provided with tools operable by the flow of air or other fluid.

It will be appreciated that water or other fluid could be readily used to create the suction instead of compressed air and this may be particularly useful where water cleaning of dirty tanks, such as oil tanks, takes place, as the tank can be initially hosed down using the "blow mode" and the dirty water can then be sucked up in the suction mode.

Claims (18)

1. A suction device having a suction opening and a compressed fluid path comprising an inlet, a restricted passage, a suction passage and an outlet, the suction passage communicating with the suction opening and the outlet and the restricted passage debouching into the suction passage intermediate the opening and the outlet, so that fluid flowing from the restricted passage is directed towards the outlet to create a depression in the suction passage to provide suction at the opening.

2. A suction device as claimed in claim 1 wherein the restricted passage surrounds the suction passage.

3. A suction device as claimed in claim 1 or claim 2 wherein the outlet of the restricted passage is directed at an angle to the axis of the suction passage.

4. A suction device as claimed in any one of the preceding claims further comprising a valve for controlling the flow of fluid in the fluid path.

5. A suction device as claimed in any one of the preceding claims wherein the device is dimensioned such that the material drawn in through the opening by the depression is delivered to the compressed fluid stream.

6. A suction device as claimed in any one of the preceding claims wherein the outlet is connected to a waste reservoir.

7. A device as claimed in claim 6 where the connection between the outlet and the reservoir is a porous pipe for retaining material sucked up by the device but which allows the escape of fluid.

8. A suction device as claimed in any one of the preceding claims further comprising selection means for substantially closing-off the suction passage from the outlet to create a jet of compressed fluid through the opening.

9. A suction device as claimed in claim 8 wherein the device includes a body and the selection means comprises a control element rotatably mounted in the body, the control element defining the downstream end of the suction passage, whereby rotation of the control element with respect to the body connects and disconnects the suction passage and the outlet.

10. A suction device as claimed in claim 9 wherein a restricted passage is defined by the body and the control element, and the control element is shaped such that rotation of it does not affect the restricted passage.

11. A device as claimed in any one of claims 8 to 10 further comprising a bleed passage for connecting the suction passage to the outlet when the selection means is in its closed off position.

12. A blow gun having a nozzle and a compressed fluid path for supplying compressed fluid to the nozzle and means for communicating the fluid path to atmosphere whenever the nozzle becomes obstructed.

13. A tool having a suction mode and a blow mode and having no moving operational parts.

14. An attachment device comprising a suction device as claimed in any one of claims 1 to 8 and further comprising a sucker or the like surrounding the suction opening.

15. A lifting device comprising an attachment device as claimed in claim 14 mounted on a lifting arm or the like.

16. A suction device substantially as hereinbefore described with reference to the accompanying drawings.

17. A blow gun substantially as hereinbefore described with reference to the accompanying drawings.

18. An attachment defined substantially as hereinbefore described with reference to the accompanying drawings.